' ( 105 ) 
At firft I took the exad Length of the Rods, in 
their natural Temper. Then I heated them as well 
as I could in a Smith’s Fire, from End to End, 
nearly to a Flaming Heat ; by which means, they 
were lengthened two Tenths of an Inch. Then I 
quenched them in cold Water; which made them 
Too of an Inch fhorter than in their natural State. 
Then I warmed them to (as near as I could guefs) 
the Femper of my Body ; by which means they 
were about 7oT of an Inch longer than in their 
natural Temper. 
Afterwards I cooled them in a ftrong frigorifick 
- Mixture of common Salt and Snow, which fliort- 
ened themioS Parts of an Inch. 
Afterwards I meafured thefe Rods, when heated in 
an hot Sun , which lengthened themTco Parts of an 
Inch more than their natural Temper. 
AlJ thefe Experiments feem to concur in refolving 
the Phenomenon of F endulum Clocks going Jlower 
under the /Equator than in the Latitudes from it : 
But yet I confefs, that I have too good an Opinion 
of Sir Ifaac Newton's Notion of the Spheroidal 
Figure of th z Earth, to part eafily with it; and 
therefore I leave it to the Confideration of others, 
how far the Figure of the Earth, and how far Heat 
and Cold, and the Rarity and Denfity of the 
Air, are concerned in that Phenomenon. 
XL The 
